Microsoft prohibits GPLed work via licensing of CIFS standards

http://www.advogato.org/article/453.html

Microsoft prohibits GPLed work via licensing of CIFS standards Posted 4 Apr 2002 by atai (Journeyer)

In its continuous battle against the GPL, Microsoft is trying a new tactic, a combination of patent claims and licensing of technical standards. In the "Royalty-Free CIFS Technical Reference License Agreement", Microsoft defines the GNU GPL as an "IPR Impairing License" and requires companies not to distribute their implementations of the CIFS specification "in any manner that would subject such Company Implementation to the terms of an IPR Impairing License." This attack is clearly aimed at the successful GPLed CIFS implementation, Samba.

The license defines

1.4 "IPR Impairing License" shall mean the GNU General Public License, the GNU Lesser/Library General Public License, and any license that requires in any instance that other software distributed with software subject to such license (a) be disclosed and distributed in source code form; (b) be licensed for purposes of making derivative works; or (c) be redistributable at no charge.

and

1.6 "Necessary Claims" shall mean those claims of a patent or patent application, including without limitation, United States Patents Nos. 5,265,261 and 5,437,013, which (a) are owned, controlled or sublicenseable by Microsoft without payment of a fee to an unaffiliated third party; and (b) are necessarily infringed by implementing the CIFS communication protocol as set forth in the Technical Reference, wherein a claim is necessarily infringed only when there are no technically reasonable alternatives to such infringement.

And it requires

3.3 IPR Impairing License Restrictions. For reasons, including without limitation, because (i) Company does not have the right to sublicense its rights to the Necessary Claims and (ii) Company's license rights hereunder to Microsoft's intellectual property are limited in scope, Company shall not distribute any Company Implementation in any manner that would subject such Company Implementation to the terms of an IPR Impairing License.